Palaeoenvironmental changes during the last 1600 years inferred from the sediment record of a cirque lake in southern Patagonia (Laguna Las Vizcachas, Argentina)

Laguna Las Vizcachas is a cirque lake located at the margin of an extra-Andean volcanic plateau in southern Patagonia, Argentina, within the area of steppe and semi-desert east of the Andes. The number of paleoenvironmental records is still limited in this region. Sediments of this lake were studied...

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Guardado en:
Detalles Bibliográficos
Publicado: 2009
Materias:
'Little Ice Age'
'Medieval Climate Anomaly'
Diatoms
Geochemistry
Lake sediments
Palaeoclimatology
Patagonia
clastic sediment
diatom
environmental change
geochemistry
hydrological change
ice cover
lacustrine deposit
Little Ice Age
paleoenvironment
precipitation (climatology)
sediment analysis
spatial analysis
Argentina
Laguna Las Vizcachas
Santa Cruz [Argentina]
South America
Bacillariophyta
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00310182_v281_n3-4_p363_Fey
http://hdl.handle.net/20.500.12110/paper_00310182_v281_n3-4_p363_Fey
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_00310182_v281_n3-4_p363_Fey
record_format dspace
spelling paper:paper_00310182_v281_n3-4_p363_Fey2023-06-08T14:56:37Z Palaeoenvironmental changes during the last 1600 years inferred from the sediment record of a cirque lake in southern Patagonia (Laguna Las Vizcachas, Argentina) 'Little Ice Age' 'Medieval Climate Anomaly' Diatoms Geochemistry Lake sediments Palaeoclimatology Patagonia clastic sediment diatom environmental change geochemistry hydrological change ice cover lacustrine deposit Little Ice Age paleoenvironment precipitation (climatology) sediment analysis spatial analysis Argentina Laguna Las Vizcachas Patagonia Santa Cruz [Argentina] South America Bacillariophyta Laguna Las Vizcachas is a cirque lake located at the margin of an extra-Andean volcanic plateau in southern Patagonia, Argentina, within the area of steppe and semi-desert east of the Andes. The number of paleoenvironmental records is still limited in this region. Sediments of this lake were studied in order to obtain multi-proxy information about the paleoenvironmental history of this site for the 'Medieval Climate Anomaly' and the 'Little Ice Age' chronozones. In combination with results from other sites across southern Patagonia, our data enhance the understanding of spatial patterns of past hydrological changes and contribute to distinguishing between the signals of temperature and precipitation. As Laguna Las Vizcachas is situated at 1100 m a.s.l. in a cool 'mountain climate', the lake system is more sensitive to changes of temperature and winter ice cover than other sites from lower elevations in this region. Our interpretation of the multi-proxy dataset is based on signals of clastic sediment input, lake productivity, organic matter sources and preservation, dilution effects and early diagenetic overprint. The record reveals a period of enhanced fluvial runoff resulting from higher precipitation from the 12th until the end of the 14th century as inferred from high concentrations of Ti, Ca, and from magnetic susceptibility. This may coincide with higher wind intensities as suggested by higher proportions of epiphytic diatoms which point to an enhanced lateral transport from their littoral habitat towards the coring position at the center of the lake. In comparison with other records from southern Patagonia, the results from Laguna Las Vizcachas suggest opposite precipitation regimes between the western and eastern parts of Patagonia during that time which corresponds partly to the 'Medieval Climate Anomaly' chronozone. However, this proposal is compromised by the chronological uncertainties of the different records under consideration. The diatom record of Laguna Las Vizcachas indicates temperature changes: highest proportions of benthic diatoms point to coldest conditions from the mid-15th until the mid-17th century, followed by relatively warm conditions until the mid-18th century as suggested by a decrease of benthic taxa and a conspicuous rise of the planktonic/non-planktonic diatom ratio that can be used as an indicator for the length or presence/absence of winter ice cover. © 2009 Elsevier B.V. All rights reserved. 2009 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00310182_v281_n3-4_p363_Fey http://hdl.handle.net/20.500.12110/paper_00310182_v281_n3-4_p363_Fey
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic 'Little Ice Age'
'Medieval Climate Anomaly'
Diatoms
Geochemistry
Lake sediments
Palaeoclimatology
Patagonia
clastic sediment
diatom
environmental change
geochemistry
hydrological change
ice cover
lacustrine deposit
Little Ice Age
paleoenvironment
precipitation (climatology)
sediment analysis
spatial analysis
Argentina
Laguna Las Vizcachas
Patagonia
Santa Cruz [Argentina]
South America
Bacillariophyta
spellingShingle 'Little Ice Age'
'Medieval Climate Anomaly'
Diatoms
Geochemistry
Lake sediments
Palaeoclimatology
Patagonia
clastic sediment
diatom
environmental change
geochemistry
hydrological change
ice cover
lacustrine deposit
Little Ice Age
paleoenvironment
precipitation (climatology)
sediment analysis
spatial analysis
Argentina
Laguna Las Vizcachas
Patagonia
Santa Cruz [Argentina]
South America
Bacillariophyta
Palaeoenvironmental changes during the last 1600 years inferred from the sediment record of a cirque lake in southern Patagonia (Laguna Las Vizcachas, Argentina)
topic_facet 'Little Ice Age'
'Medieval Climate Anomaly'
Diatoms
Geochemistry
Lake sediments
Palaeoclimatology
Patagonia
clastic sediment
diatom
environmental change
geochemistry
hydrological change
ice cover
lacustrine deposit
Little Ice Age
paleoenvironment
precipitation (climatology)
sediment analysis
spatial analysis
Argentina
Laguna Las Vizcachas
Patagonia
Santa Cruz [Argentina]
South America
Bacillariophyta
description Laguna Las Vizcachas is a cirque lake located at the margin of an extra-Andean volcanic plateau in southern Patagonia, Argentina, within the area of steppe and semi-desert east of the Andes. The number of paleoenvironmental records is still limited in this region. Sediments of this lake were studied in order to obtain multi-proxy information about the paleoenvironmental history of this site for the 'Medieval Climate Anomaly' and the 'Little Ice Age' chronozones. In combination with results from other sites across southern Patagonia, our data enhance the understanding of spatial patterns of past hydrological changes and contribute to distinguishing between the signals of temperature and precipitation. As Laguna Las Vizcachas is situated at 1100 m a.s.l. in a cool 'mountain climate', the lake system is more sensitive to changes of temperature and winter ice cover than other sites from lower elevations in this region. Our interpretation of the multi-proxy dataset is based on signals of clastic sediment input, lake productivity, organic matter sources and preservation, dilution effects and early diagenetic overprint. The record reveals a period of enhanced fluvial runoff resulting from higher precipitation from the 12th until the end of the 14th century as inferred from high concentrations of Ti, Ca, and from magnetic susceptibility. This may coincide with higher wind intensities as suggested by higher proportions of epiphytic diatoms which point to an enhanced lateral transport from their littoral habitat towards the coring position at the center of the lake. In comparison with other records from southern Patagonia, the results from Laguna Las Vizcachas suggest opposite precipitation regimes between the western and eastern parts of Patagonia during that time which corresponds partly to the 'Medieval Climate Anomaly' chronozone. However, this proposal is compromised by the chronological uncertainties of the different records under consideration. The diatom record of Laguna Las Vizcachas indicates temperature changes: highest proportions of benthic diatoms point to coldest conditions from the mid-15th until the mid-17th century, followed by relatively warm conditions until the mid-18th century as suggested by a decrease of benthic taxa and a conspicuous rise of the planktonic/non-planktonic diatom ratio that can be used as an indicator for the length or presence/absence of winter ice cover. © 2009 Elsevier B.V. All rights reserved.
title Palaeoenvironmental changes during the last 1600 years inferred from the sediment record of a cirque lake in southern Patagonia (Laguna Las Vizcachas, Argentina)
title_short Palaeoenvironmental changes during the last 1600 years inferred from the sediment record of a cirque lake in southern Patagonia (Laguna Las Vizcachas, Argentina)
title_full Palaeoenvironmental changes during the last 1600 years inferred from the sediment record of a cirque lake in southern Patagonia (Laguna Las Vizcachas, Argentina)
title_fullStr Palaeoenvironmental changes during the last 1600 years inferred from the sediment record of a cirque lake in southern Patagonia (Laguna Las Vizcachas, Argentina)
title_full_unstemmed Palaeoenvironmental changes during the last 1600 years inferred from the sediment record of a cirque lake in southern Patagonia (Laguna Las Vizcachas, Argentina)
title_sort palaeoenvironmental changes during the last 1600 years inferred from the sediment record of a cirque lake in southern patagonia (laguna las vizcachas, argentina)
publishDate 2009
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00310182_v281_n3-4_p363_Fey
http://hdl.handle.net/20.500.12110/paper_00310182_v281_n3-4_p363_Fey
_version_ 1768545133032112128

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